Weather App

              

An Android weather application built with Kotlin that provides real-time weather data and detailed atmospheric metrics based on your current GPS location. No API key required.

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📸 App Preview

       

📱 Screens

Screen	Description
Home	App entry point
Weather	Current temperature + 8 key weather stats
Details	12 advanced metrics in scrollable cards

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✨ Features

• Real-time weather fetched from your GPS location
• Two levels of weather data: basic overview and advanced details
• Scrollable card-based UI for detailed metrics
• Bottom navigation between screens
• Portrait-locked orientation for consistent layout
• No API key needed

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🛠️ Tech Stack

Tool	Purpose
Kotlin	Primary language
XML	UI layouts
Gradle	Build system
Android Studio	IDE
Open-Meteo API	Free weather data, no API key
Google Play Services	Fused Location Provider for GPS
Material Design 3	UI components (cards, bottom nav)
RecyclerView	Scrollable advanced data cards
ConstraintLayout	Responsive screen layouts

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🌐 API — Open-Meteo

This app uses the free Open-Meteo API — no account or API key required.

Screen 1 — Weather Overview (MainActivity2)

Fetches basic current conditions and today's minimum temperature.

Endpoint:

GET https://api.open-meteo.com/v1/forecast
  ?latitude={lat}
  &longitude={lon}
  &current=temperature_2m,relative_humidity_2m,wind_speed_10m,rain,dew_point_2m,sunshine_duration
  &daily=temperature_2m_min

Data used:

Field	Source	Unit	Displayed As
temperature_2m	current	°C	Main temperature
rain	current	mm	Rain amount
relative_humidity_2m	current	%	Humidity
wind_speed_10m	current	km/h	Wind speed
dew_point_2m	current	°C	Dew point
sunshine_duration	current	s	Sunshine span
temperature_2m_min	daily[0]	°C	Min temperature

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Screen 2 — Advanced Details (MainActivity3)

Fetches deeper atmospheric data from current, daily, and hourly fields.

Endpoint:

GET https://api.open-meteo.com/v1/forecast
  ?latitude={lat}
  &longitude={lon}
  &current=apparent_temperature,precipitation,showers,snowfall,cloud_cover,direct_radiation,surface_pressure,pressure_msl
  &daily=daylight_duration,uv_index_max
  &hourly=cape,soil_temperature_0cm

Data used:

Field	Source	Unit	Displayed As
apparent_temperature	current	°C	Apparent Temp
precipitation	current	mm	Precipitation
showers	current	mm	Showers
snowfall	current	cm	Snowfall
cloud_cover	current	%	Cloud Cover
direct_radiation	current	W/m²	Radiation
surface_pressure	current	hPa	Surface Pressure
pressure_msl	current	hPa	Sea Level Pressure
daylight_duration	daily[0]	s	Daylight Span
uv_index_max	daily[0]	-	UV Index Max
cape	hourly[0]	J/kg	Storm Energy
soil_temperature_0cm	hourly[0]	°C	Soil Temp 0cm

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💻 Code Snippets

Fetching location

fusedLocationClient.lastLocation
   .addOnSuccessListener { location ->
      if (location != null) {
         fetchData(location.latitude, location.longitude).start()
      }
   }

Making the API request

val url = URL(
   "https://api.open-meteo.com/v1/forecast?" +
           "latitude=$lat&longitude=$lon&" +
           "current=apparent_temperature,precipitation,showers,snowfall," +
           "cloud_cover,direct_radiation,surface_pressure,pressure_msl&" +
           "daily=daylight_duration,uv_index_max&" +
           "hourly=cape,soil_temperature_0cm"
)
val connection = url.openConnection() as HttpsURLConnection

Parsing the JSON response

val json = org.json.JSONObject(reader.readText())

val current = json.getJSONObject("current")
val daily   = json.getJSONObject("daily")
val hourly  = json.getJSONObject("hourly")

val weather = WeatherAdvanced(
   apparentTemp     = current.optDouble("apparent_temperature", 0.0),
   precipitation    = current.optDouble("precipitation", 0.0),
   cloudCover       = current.optDouble("cloud_cover", 0.0),
   daylightDuration = daily.getJSONArray("daylight_duration").optDouble(0, 0.0),
   uvIndexMax       = daily.getJSONArray("uv_index_max").optDouble(0, 0.0),
   cape             = hourly.getJSONArray("cape").optDouble(0, 0.0),
   soilTemp         = hourly.getJSONArray("soil_temperature_0cm").optDouble(0, 0.0)
)

Data classes

data class Weather(
   val temp: Double,
   val rainAmount: Double,
   val humidity: Double,
   val windSpeed: Double,
   val dewPoint: Double,
   val sunshineSpan: Double,
   val tempMin: Double
)

data class WeatherAdvanced(
   val apparentTemp: Double,
   val precipitation: Double,
   val showers: Double,
   val snowfall: Double,
   val cloudCover: Double,
   val directRadiation: Double,
   val daylightDuration: Double,
   val surfacePressure: Double,
   val pressureMsl: Double,
   val uvIndexMax: Double,
   val cape: Double,
   val soilTemp: Double
)

Updating the UI on the main thread

private fun UpdateUI(weather: Weather, lat: Double, lon: Double) {
   runOnUiThread {
      findViewById<TextView>(R.id.Degree).text        = "${weather.temp}°C"
      findViewById<TextView>(R.id.rain_amount).text   = "${weather.rainAmount}mm"
      findViewById<TextView>(R.id.humidity_amount).text = "${weather.humidity}%"
      findViewById<TextView>(R.id.wind_amount).text   = "${weather.windSpeed}km/h"
      findViewById<TextView>(R.id.dew_amount).text    = "${weather.dewPoint}°C"
      findViewById<TextView>(R.id.sun_span).text      = "${weather.sunshineSpan}s"
      findViewById<TextView>(R.id.min_temp).text      = "${weather.tempMin}°C"
      findViewById<TextView>(R.id.latitude).text      = "Latitude:%.2f".format(lat)
      findViewById<TextView>(R.id.longtitude).text    = "Longitude:%.2f".format(lon)
   }
}

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📂 Structure Snippet

app/
├── manifests/
│   └── AndroidManifest.xml
├── kotlin/com/example/weatherapp/
│   ├── MainActivity.kt          # Home screen
│   ├── MainActivity2.kt         # Weather overview screen
│   ├── MainActivity3.kt         # Advanced details screen
│   ├── WeatherAdapter.kt        # RecyclerView adapter
│   ├── Weather.kt               # Basic weather data class
│   ├── WeatherAdvanced.kt       # Advanced weather data class
│   ├── WeatherData.kt           # RecyclerView item data class
│   └── Navigate.kt              # Bottom nav helper
└── res/
    ├── layout/
    │   ├── activity_main.xml
    │   ├── activity_main2.xml
    │   ├── activity_main3.xml
    │   └── data_card.xml
    ├── menu/
    │   └── bottom_nav.xml
    └── color/
        └── nav_item_color.xml

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🔑 Permissions

Declared in AndroidManifest.xml:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>

Location permission is also requested at runtime:

ActivityCompat.requestPermissions(
   this,
   arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
   1
)

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🚀 Getting Started

Prerequisites

• Android Studio (Hedgehog or newer recommended)
• Android SDK 24+
• A physical Android device or an emulator with location mocking enabled

Steps

1. Clone the repository

   git clone https://github.com/yourusername/weatherapp.git

2. Open in Android Studio

   • File → Open → select the project folder

3. Let Gradle sync

   • Android Studio will automatically download dependencies

4. Run the app

   • Connect a physical device via USB with USB debugging enabled
   • Or launch an emulator
   • Press Run ▶ or Shift + F10

5. Grant permissions

   • Accept the location permission prompt on first launch

⚠️ A physical device gives the most accurate GPS results. Emulators require manual location mocking via Extended Controls.

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📦 Dependencies

In build.gradle (app):

dependencies {
    implementation 'com.google.android.gms:play-services-location:21.0.1'
    implementation 'com.google.android.material:material:1.11.0'
    implementation 'androidx.recyclerview:recyclerview:1.3.2'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
}

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📄 License

This project is open source and free to use for personal and educational purposes.

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Weather data provided by Open-Meteo — free and open-source weather API, no key required.